Health management is a modern phrase for condition monitoring and maintenance management. Health management in the industrial equipment world typically involves a set of processes, hardware, and software tools that perform data analysis, diagnosis, assessment, prognosis, and decision-making. A health management system is sometimes called a condition monitoring system (CMS).
With the recent emphasis on prognostics, a health management system is also called a prognostics and health management (PHM) system; and in the context of equipment maintenance, it is called a condition based maintenance (CBM) system. The concept of a CBM system is to manage the consequence of a fault and perform maintenance, only if there is an evidence of need for repair or replacement. This concept is illustrated in FIG. 1.
The benefits of equipment health management are improved availability, increased efficiency, and reduced cost of ownership. To realize these benefits, the various health management functions, as illustrated in FIG. 1, must be efficiently integrated and timely updated with new information. Many monitoring techniques have been developed to facilitate CBM or PHM capability; however, most of these techniques suffer from the problem of frequent false alarms (or false positive diagnosis), because the equipment's operational data are noisy and the system being monitored is often complex. False alarms are undesirable because they waste human and facility resources in trying to analyze and troubleshoot the alarms, and these extra efforts often result in no-fault-found (NFF) or can-not-duplicate (CND).
Thus, there is a need to reduce false alarms in a condition monitoring or health management system. This need for more accurate monitoring of equipment condition is present not just for the aerospace industry, but is prevalent for other industries as well, including, but not limited to, sea and land transportation, process industry, manufacturing, and human health care.